1. Field of the Invention
The present invention relates to molded fiber materials that may be utilized, e.g., as a trim material, such as door trim for automobiles, a construction material, such as wall material for houses, and furniture. The present invention further relates to methods and apparatus for manufacturing such molded fiber materials.
2. Description of the Related Art
Known fiber laminates (graded mats) provide variations in concentration of a natural fiber and a thermoplastic fiber across the thickness or depth of the fiber laminate by adhering a plurality of discrete layers. As shown in FIG. 9, a known fiber laminate 100 has been manufactured by adhering a plurality of layers 101-103 that were separately and individually manufactured in advance. Each layer 101-103 has a substantially uniform concentration or mixture of the natural and thermoplastic fibers, although the concentration or mixture of the natural and thermoplastic fibers of each respective layer 101-103 differs. For example, the front and rear sides of the fiber laminate 1000 may be formed of a relatively thermoplastic fiber-rich layer 101 (i.e., layer 101 contains more thermoplastic fiber than natural fiber). Further, the interior layers 102-103 may have higher concentrations of natural fiber than thermoplastic fiber. Such fiber laminates have been used as trim materials, such as door trim materials for automobiles.
However, the known fiber laminate 100 is disadvantageous, because it is necessary to separately manufacture each of the layers 101-103 and each respective layer 101-103 requires a different concentration and a separate manufacturing process. Thereafter, the respective layers 101-103 must be adhered together in another manufacturing step. Therefore, known fiber laminate manufacturing processes require many steps, thereby complicating the production process and reducing productivity.